"Teachers normally are there in the classroom for the kids so this is a really hard decision for teachers to make," she said. "This is something that they do not take lightly."

The South Orange County school district of 52,000 students is facing a $34 million budget deficit next fiscal year. An independent mediator had recommended both sides approve a 6 percent pay cut and an increase in class sizes to help close the state funding gap.

Capistrano Unified School Board President Anna Bryson said the union might disagree over the pay cuts but she and and the board had to do keep the district solvent.

Administrators, she said, are preparing campuses for a strike.

"We’ll keep the doors open," she said. "We have a complete plan in place that will make sure there are teachers in those classrooms. They will have lesson plans and the whole process of educating will go forward."

Union leaders expect vigorous debate at Thursday’s member meeting. A vote in favor would give union leaders authority to call for a strike at their discretion.